1. **IONIC BONDS
Only certain ratios (combinations) of elements result in the formation of Ionic compounds.
For ex: Lithium (Li) will react with Fluorine (F) to form LiF.
BUT, it will NOT form LiF2, LiF3, etc.
Magnesium (Mg) will react with Fluorine to form MgF2.
BUT, it will NOT form MgF, MgF3, etc.

2. Carbon, Hydrogen, Nitrogen, Oxygen
**Warm up Questions
Without using your notes, answer the following questions. Write the questions!
What is a compound?
Two or more DIFFERENT atoms (elements) that are chemically bonded together because of a chemical reaction.
2. Which formula is a compound and why?
C8H10N4O2 or F2
C8H10N4O2= compound
3. What are the element(s) that make up each chemical formula in question 2?
Carbon, Hydrogen, Nitrogen, Oxygen
Fluorine

3. IONIC BONDS
What could you do to get the charges to cancel out if you wanted to form this ionic compound???
Li+1 + O-2
ANSWER: You would need to use
2 Li+1 for every O-2!!!
= Li2O

4. Compound Name and chem. formula
**Getting Connected
Element 1
(metal)
# of valence e-
Element 2
(nonmetal)
Compound Name and chem. formula
Total # of valence e- Na 1 F 7
NaF 8

5. COVALENT BONDS Form between two non-metals or between molecules.
Bond because the outer electron rings are not full so they share valence e-
**Form by sharing valence electrons
(The atoms are NOT stable.)

6. Properties of COVALENT BONDS
These are weak bonds.
Covalent compounds will have low melting and boiling points.
Some examples are H2O (water/ wudder), and
CO2 (Carbon Dioxide)

7. COVALENT BONDS The reason H2O is covalent:
Remember H can be a metal or a non-metal!!!
Here H is behaving like a non-metal.
Hydrogen is usually a non-metal!

8. 1.) NH3 7.) BeO 2.) NaCl 8.) P2O5 3.) CH4 9.) Li3P 4.) CO2 10.) BN
Let’s Practice! Write the following compounds and determine if they are Ionic or Covalent?
1.) NH ) BeO
2.) NaCl ) P2O5
3.) CH ) Li3P
4.) CO ) BN
5.) CaCl ) N2O
6.) KBr ) MgS

9. ANSWERS… 1.) NH3 Covalent 2.) NaCl Ionic 3.) CH4 Covalent
4.) CO2 Covalent
5.) CaCl2 Ionic
6.) KBr Ionic
7.) AlCl3 Ionic
8.) P2O5 Covalent
9.) Li3P Ionic
10.) BN Covalent
11.) N2O Covalent
12.) MgS Ionic

10. Covalent vs. Ionic (Four Corners)
2 non-metals
share val. e ions w/ opposite charges
weak bonds
1000C (low) boiling pts.
ionic
metal and nonmetal
transferring val. e’
strong bonds
14650C (high) boiling pts.

11. Lewis Structures Electron Dot Diagrams
We will show how the atoms share electrons by drawing electron dot diagrams.
You will only use the valence e- for dot diagrams.

12. Dot Diagrams
Start the dot diagram by writing the atomic symbol for the atom.
Ex: Mg
The symbol has 4 sides…

13. Dot Diagrams Mg Each side can hold up to 2e-
You cannot pair the electrons until there is one on each side. 1 3 4

14. Dot Diagrams Mg Mg only has 2 valence e-.
So it’s dot diagram looks like this:
Let’s try… Si
how about… S 1 3 4

15. Dot Diagrams Practice!!! Draw the Dot Diagrams for:
Cl b) C
c) Al d) Ne
e) Na f) N

16. Dot Diagrams
How did you do???
a) Cl b) C
c) Al d.) Ne
e.) Na f.) N

17. Dot Diagrams Practice ProblemsK Sr B Si P S Kr Ca O

18. Dot Diagrams
Now we can put individual diagrams together to show whether atoms transfer or share their valence e-!!!

19. Dot Diagrams for Ionic Bonds
We know that in an Ionic Bond atoms are transferring their valence e- …
We use a arrows between the Atomic Symbols to represent the transferring of e-.
We can show this w/ dot diagrams.
For Ex: (Li + Cl = LiCl) Cl Li

20. **Dot Diagram Practice for Ionic Bonds
BeO
NaCl
MgS
CaCl2
Li3P
AlCl3